| 
           Hedging Activities (Narrative) (Details) (USD $) 
        In Millions, unless otherwise specified  | 
        3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
| 
           Sep. 30, 2014 
         | 
        
           Sep. 30, 2013 
         | 
        
           Sep. 30, 2014
 
          financial_institution 
         | 
        
           Sep. 30, 2013 
         | 
        
           Dec. 31, 2013
 
          financial_institution 
         | 
      |
| General Discussion of Derivative Instruments and Hedging Activities [Abstract] | |||||
| Number of financial institutions | 4 | 4 | |||
| Gain on fair value hedge ineffectiveness, net | $ 29.5 | $ (6.7) | $ 23.0 | $ (1.3) | |
| X | ||||||||||
| 
             
- Definition 
          Number Of Financial Institutions No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
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- Details 
          
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